According the of the art, waste is transported to the dump by vehicles and compacted to the highest possible density after delivery or unloading and/or pretreatment. The compacting is carried out using rammer foot compacters and caterpillar tracks. When compacting surfaces, the waste is spread on horizontal or inclined working surface and comminuted by ramming several times with the rammer foot compacter, pressed together and compacted. For co-compacting non-comminutable bulky waste and muds, a tipping edge compacter can also be used temporarily. In the process the solid waste is compacted so that it is pushed from the part of the working surface which is already compacted over a so-called tipping edge. The solid waste is thus removed approximately 10 m in front of the tipping edge, comminuted by ramming several times and only then pushed over the tipping edge. The incline thus formed should be compacted and covered at least at the end of the working day. Bulky waste and muds are unloaded at the foot of the tipping edge and are showered with material from above.
In spite of the compacting measures described, subsidence still occurs in the body of the dump over a long period when material is no longer added. This has an unfavourable effect on the surface and intermediate covers and on shaft and channel systems. Part of the subsidence, caused by mechanical processes, can be anticipated by subsequent deep compaction of the dump body.
This compaction technique comprises in allowing falling masses of, for example 20 tonnes, to fall from, for example 20 m onto the waste surface, as a result of which loading pulses are produced which should effect compaction to a great depth. However, when using this process, installations, such as base sealing, a drainage system and a gas-removing system, in the dump body, must be taken into account. Distances between a compacting point and the abovementioned devices should be at least 10 m vertically and horizontally. This compacting technique should therefore be virtually excluded if permanent intermediate seals are incorporated into the dump body in layers approximately every 10 m.
The possibility of pretreatment of waste before disposal is also known. Hence, certain waste materials must be pretreated before they can be deposited on a dump. Chemico-physical treatment plants are used for pretreatment purposes, such as for example neutralising, detoxification, drainage, solidifying.
Chemico-physical treatment plants (CPT) are--as a rule fixed (but also mobile)--plants having technical devices for chemical and physical treatment of waste (without combustion and pyrolysis), the aims of which are utilisation and/or environmentally acceptable waste management.
CPT have the aim of treating waste, in particular special waste, under the following guidelines:
as high as possible utilisation PA1 reducing the amount of waste to be disposed of PA1 reducing the danger potential PA1 making further treatment and utilisation steps possible (for example combustion) or other environmentally acceptable waste management (for example disposal).
Various chemical and physical processes are suitable for the treatment, individually or in combination. They are essentially the following processes: